Ultrashort wave system



May 3, 1938. H SCHARLAU ULTRASHORT WAVE SYSTEM Filed May 14, 1956INVENTOR HANS SCHARLA-U 7%? m' L/ ATTORNEY RECEIVER Patented May 3, 1938UNITED STATES ULTRASHORT WAVE SYSTEM Hans Scharlau, Berlin, Germany,assignor to Telefunken Gesellschaft fur Drahtlose Telegraphic m. b. H.,Berlin, Germany, a corporation of Germany Application May 14, 1936,Serial No. 79,634 In Germany June 8, 1935 2 Claims.

The present invention is concerned with an arrangement adapted toreceive electrical waves, especially ultra short waves, from alldirections.

In order to insure reception of electromagnetic waves from all and anydirection it has been customary in the prior art to use for thereceiving aerial simple wires and dipoles, and for the reception ofgreater energies wires of a length equal to several waves, and also rowsof dipoles.

In order to pick up uniform volumes of energy from all directions, it isnecessary that the said antenna arrangements be mounted vertically.

Of course, it will be feasible only in this way to pick up verticallypolarized waves. If, for one reason or another, horizontally orobliquely polarized waves are also to be received, the said arrangementsof the prior art fail to operate.

1 According to the present invention, waves com- I ing in from differentdirections and polarized in various ways can be picked up by the aid ofa conical reflector which reflects them onto a receiving arrangementwhich is fundamentally known in the art and which is responsive to wavesof any direction of polarization. Such an arrangement, for instance, mayconsist of two crossed dipoles which are caused to act upon the receiverwith a phase displacement angle of 90.

Figs. 1 and 2 show two different embodiments of the invention.

Fig. 1 shows an arrangement of this invention for waves coming in fromdifferent directions and which is built into a railway car. K is aconeshaped reflector which will reflect a wave com- .ing in from anytransmitter S at all into the interior of the car by way of theparabolic reflector Sp onto the crossed dipoles D which are united withthe receiver E. Since a conical reflector is built circularlysymmetrical, the waves may come in from all possible directions. Bymeans of the Z crossed dipoles, the directions of polarization of theincoming waves are immaterial for effecting reception.

Fig. 2 shows a similar embodiment by way of example. In the powerpropelled car A, in the focus of the concave mirror Sp, is disposed thedipole cross D which is associated with the receiver E. In lieu of thecone reflector K of Fig. 1, there is provided a rotary reflectingstructure 7 F similar to the lift screw or propeller of a l helicoptertype airplane. The reflecting vanes or blades I, 2, 3 4 and 5 could, forinstance, be cut out of a conical shell, but the breadth of theconstituent vanes at the reflecting points must be at least equal to M2in order that they may also reflect horizontally polarized waves. Therev lows: From a transmitter S a wave-train, say,

unmodulated in nature, shall be assumed to strike one of the vanes ofthe mirror wheel F and is thus reflected into the interior of the car A.Inasmuch as the wheel revolves, the vanes continue rotating and thewave-train no longer 5 reaches the receiver. Then the second vanebecomes efiective and operative, and so on. The result is that briefimpulses of waves are received which act in such a fashion as though thetransmitter were modulated at a frequency which 10 is equal to the rateof rotation per second of the vaned wheel multiplied by the number ofthe vanes. Also, in the case of this arrangement it is, fundamentallyspeaking, immaterial from which direction the waves impinge upon the 15vaned wheel or reflector wheel. A considerable advantage results also inthat the incoming wave by the modulation of the reflector wheel iscompletely modulated.

Of course, the embodiments hereinbefore shown 20 and described do notexhaust the basic idea of this invention. For example, in lieu of aconeshaped reflector also a pyramidal reflector could be employed which,in addition, could be rotatable. Also, for the receiving aerial to pickup the waves, recourse could be had to other dispositions, say, a"Christmas tree type of aerial, although crossed dipoles would have tobe used in the latter rather than individual dipoles or else two crossedChristmas tree type antennae in order to render the assembly independentof the polarization of the incoming waves.

What is claimed is:

1. In combination, in a short wave receiving system, a reflector in theform of a cone, said re- 35 flector comprising a plurality of spacedreflecting blades arranged in the surface of said cone, said reflectorbeing rotatable around the axis passing through the apex thereof,whereby the waves impinging on said reflector are modulated at a 40frequency which is a function of the rate of rotation of said reflectorand the spacing of said blades, and an arrangement substantiallysymmetrically positioned with respect to the 'apex of said conicalreflector for receiving waves of any 5 polarization impinging upon theblades of said conical reflector.

2. In combination, in a short wave receiving system, a. reflector in theform of a cone, said reflector comprising a plurality of spacedreflecting 50 blades arranged in the surface of said cone, and anarrangement substantially symmetrically positioned with respect to theapex of said conical reflector for receiving waves of any polarizationimpinging upon the blades of said conical re- 55 flector, said bladeshaving a width at one portion at least as wide as half the length of thecommunication wave.

HANS SCHARLAU. 60

